Japanese scientists are shedding new light on tiny, hidden tumors that might otherwise go unseen by the eyes of surgeons and even magnetic-resonance imaging (MRI) with a new spray that makes the carcinomas glow fluorescent green.

At this point, researchers say they have yet to identify any serious side-effects resulting from the spray.

While this process may be the quickest method yet developed, it's not the first time scientists have experimented with making cancer cells glow. Earlier this month, scientists began testing a technique to make brain tumors glow. That process, however, requires patients to take a drug that causes "a build-up of fluorescent chemicals in the tumour, making it glow pink."

WATCH: (WARNING: The video below is not for the squeamish, as it depicts researchers examining a dissected lab mouse.)